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US 5,049,507 AGranted
Method of C-terminal peptide sequencing
AssigneeApplied Biosystems, LLC
InventorsDavid H. Hawke, Victoria L. Boyd
Life of this patent
Estimating the term…
Abstract
A method of C-terminal peptide sequencing. The peptide is reacted with a mixed anhydride of isothiocyanic acid and a carboxylic, carbonic, or sulfonic acid, under basic conditions, to produce a C-terminal peptidyl thiohydantoin. The C-terminal amino acid can be identified by cleaving the thiohydantoin from the peptide and identifying the free amino acid thiohydantoin.
Claims13
A method of determining the C-terminal amino acid residue of a peptide, comprising
- reacting the peptide with a mixed anhydride of isothiocyanic acid and an acid selected from the group consisting of carboxylic, carbonic, and sulfonic acid, under basic conditions in which the C-terminal acid group of the amino acid is deprotonated, to form a peptidyl thiohydantoin in which the C-terminal amino acid has been converted to a C-terminal amino acid thiohydantoin which is linked to the next-in amino acid in the peptide through an amide bond,
- treating the peptidyl thiohydantoin under conditions effective to cleave said amide bond, thereby releasing a C-terminal amino acid thiohydantoin and a reduced-length peptide, and
- identifying the released amino acid thiohydantoin.
A method of producing a thiohydantoin (TH) of a protected amino acid having a free carboxylic acid group, comprising
- contacting the amino acid in solution with a mixed anhydride of isothiocyanic acid and carboxylic, carbonic or sulfonic acid, under basic conditions in which the carboxylic acid group of the amino acid is deprotonated, and
- by said contacting, forming the TH of the amino acid in solution.
Dependencies are inferred from the claim text.